Top-level modeling theory of multi-discipline virtual prototype

Multi-disciplinary virtual prototypes of complex products are increasingly and widely used in modern advanced manufactur- ing. How to effectively address the problems of unified modeling, composition and reuse based on the multi-disciplinary heteroge- neous models has brought great challenges to the modeling and simulation （M＆S） science and technology. This paper presents a top-level modeling theory based on the meta modeling framework （M2F） of the COllaborative SIMulation （COSlM） theory of virtual prototyping to solve the problems. Firstly the fundamental prin- ciples of the top-level modeling theory are decribed to expound the premise, assumptions, basic conventions and special require- ments in the description of complex heterogeneous systems. Next the formalized definitions for each factor in top level modeling are proposed and the hierarchical nature of them is illustrated. After demonstrating that they are self-closing, this paper divides the top- level modeling into two views, static structural graph and dynamic behavioral graph. Finally, a case study is discussed to demon- strate the feasibility of the theory.

BIM Improved with RV and AR Technologies

The study addresses the integration of the Building Information Modelling (BIM) methodology with Virtual Reality (VR) and Augmented Reality (AR) technologies in the context of the development of a multidisciplinary project, involving architecture, structures, water network and electrical system components. In order to cover in detail the various design features, the case study was limited to a specific area of a house, the sanitary rooms, as it presents sufficient complexity in modeling and the application of VR and AR software. The VR/AR functionalities applied over the BIM model increase the potential of BIM in the construction sector, contributing to the achievement of a high level of collaboration and control of the project based on an immersive and interactive environment. The elaboration of the different phases of a BIM design requires the transfer of models between BIM and VR/AR systems, allowing us to analyze the main advantages that BIM/VR/AR integration can introduce in the construction industry. The study contributes positively to achieving new knowledge in BIM, being disseminated in an academic research work and illustrated in a practical context.

Immersive Virtual Product Development

Immersive virtual product development is a new desi gn , developing and evaluation method of integrated product and processing tragedie s, which using VR, multi-discipline simulation and scientific visualization tec hnologies. Users may have the experiences of being part of a cyberspace environm ent with the ability to navigate and manipulate objects which have properties an d behaviors that correspond to those of the real world objects. We present a fra mework and prototype system of an immerse VPD (IVPD) which enables users to navi gate and interact with 3D peripherals with the display system. The framework of IVPD which we have defined can meet these requirements. In the immersive virtual environment, design will include four main parts: 3D CAD/modeler, multidiscipli ne simulations, CAM and discrete system simulation. 3D CAD/modeler can create 3D geometric objects and import models from other commercial softwares such as UG, CATIA etc. It can also store all kinds of models into databases with hierarchy which will provide geometric models with simulations and evaluations in later pr ocedures. Multidiscipline simulations can integrate many simulations such as FEA , CFD, Noisy and etc. Each kind of these simulation softwares will reflect a cer tain aspect of product or component’s performances. CAM, as a successor of prod uct development, mainly simulates the manufacturing procedures in the computer. Discrete system simulation will able to see the layout problems for a factory. I t is very useful for production management. Participants may actively view the v irtual world revolving around them while others control navigation and simul ations, and may interact with other members such as pass an object from one embo died manikin to another.

External penetrating laryngeal trauma caused by a metal fragment:A Case Report

BACKGROUND Although external penetrating laryngeal trauma is rare in the clinic,such cases often result in a high mortality rate.The early recognition of injury,protection of the airway,one-stage laryngeal reconstruction with miniplates and interdisciplinary cooperation are important in the treatment of such patients.CASE SUMMARY A 58-year-old male worker sustained a penetrating injury in the left neck.After computed tomography scanning at a local hospital,he was transferred to our hospital,where he underwent tracheotomy,neck exploration,extraction of the foreign object,debridement and repair of the thyroid cartilage using titanium miniplates.An endo laryngeal stent was inserted,which was removed 12 days later.The patient recovered well and his voice rapidly improved after surgery.CONCLUSION Penetrating laryngeal trauma is uncommon.We successfully treated a patient with early laryngeal reconstruction and management by interdisciplinary cooperation.

Feature analysis on US military aircraft engine advanced technology programs

US military aircraft engine advanced technology programs were overviewed and analyzed from light weight gas generator(LWGG)program initiated in 1960 sthrough integrated high performance turbine engine technology(IHPTET)program started in 1980 s,then to versatile affordable advanced turbine engine(VAATE)program.Some features and trends were summarized and concluded by literature statistics method,such as teams based on closely corporation among government,industries and academics,goals oriented with national defence strategies and weapon system development requirements,engineering manufacture and development including all relative disciplines and areas,verification measured by technology readiness level,the application extending to military aircraft engine,civilian engine,gas turbine and space vehicle,etc.The experience and lessons obtained can provide reference and guide for technology research and engineering manufacture and development of military aircraft engines in the world.